Research NEWS

Tag Archives: Health

Serious air pollution, like this smog over China’s capital city, may increase the risk of obesity.

Air pollution is bad for our lungs. It may not be great for our waistlines either, a new study in rats finds.

China’s capital city of Beijing has some of the worst air pollution in the world. On really bad days, its air can host more than 10 times as many tiny pollutant particles as the World Health Organization says is safe for human health. In a new study, rats breathed in this air. And those rodents gained more weight, and were unhealthier overall, than were rats breathing much cleaner air. The results suggest that exposure to air pollution can raise the risk of becoming extremely overweight.

And, adds Loren Wold, “It is highly likely that this is happening in humans.”

Wold works at Ohio State University in Columbus. There, he studies how air pollution affects the heart. He was not involved in the new study. But he says it agrees with many other studies that have suggested air pollution can affect metabolism, which is how the body breaks down food and uses it for fuel.

Polluted air contains particles of ash, dust and other chemicals. Sometimes these particles are so numerous that they create a thick, dense smog can cuts visibility.

Earlier experiments among 18-year olds in Southern California had linked heavier traffic with higher body mass index (a measure of overweight and obesity). Areas with heavy traffic also tend to have more of those pollutant particles. Another study found that when pregnant mice were exposed to exhaust from diesel engines, their pups grew up to be heavier. The pups also developed more inflammation in their brains.

In the new study, researchers tested how Beijing’s polluted air affects the health of pregnant rats.

Jim Zhang is an environmental scientist at Duke University in Durham, N.C. He and his co-workers put rats in two indoor chambers in Beijing. They piped polluted air from the city directly into one chamber. Air piped into the other chamber went through a filter. That filter removed almost all of the big pollution particles from the air and about two-thirds of the smaller ones. This made the air more like what people breathe in typical U.S. cities and suburbs, Zhang says.

All rats ate the same type and amount of food. But after 19 days, the pregnant rats breathing the heavily polluted air weighed more than the rats breathing the filtered air. They also had higher amounts of cholesterol — a waxy, fatlike substance — in their blood than did the rats breathing filtered air.

Those breathing the dirtier air had higher levels of inflammation. This is a sign of the body responding to tissue damage. These rats also had higher insulin resistance. This means their bodies weren’t responding as well to insulin, a hormone that helps with using sugar for energy. Insulin resistance can lead to diabetes, a dangerous health condition.

Taken together, the scientists say, these symptoms indicate the rats were developing metabolic syndrome. It’s a condition that puts the animals at risk of heart disease and diabetes.

During the experiment, the pregnant rats gave birth. Their pups stayed in the chambers with their mothers. And young rats that breathed in the polluted air were heavier than pups born to moms living in the cleaner air. Like their moms, the pups breathing very polluted air had more inflammation and insulin resistance.

The longer these pups breathed the dirty air, Zhang says, the more unhealthy they became. This suggests that breathing polluted air for a long time can lead to sickness, Zhang says.

It’s not yet clear exactly how air pollution affects rat metabolism. But it seems, Zhang says, to impair how the animals process fat and sugar. Pollution also increases signs of inflammation in the lungs, blood and fat. Zhang says this is probably what led to weight gain in the animals.

Wold says it might be possible to create medicines that reverse the negative health effects of air pollution. But these medicines will take time to develop.

Until then, Zhang and Wold say that paying attention to air pollution levels can help people manage their health risks. On days when pollution levels are high, they recommend that people stay indoors, if possible — or at least avoid tough outdoor exercise .

Like this:

One of several antibiotic treatment options for the sexually transmitted disease gonorrhea seems to be losing its effectiveness, U.S. health officials warn in a new report.

The U.S. Centers for Disease Control and Prevention’s latest tracking suggests that although resistance to the antibiotic treatment cefixime went down between 2011 and 2013, it started to creep back up in 2014.

The good news is that cefixime isn’t usually the first drug of choice for treating gonorrhea infections. The CDC’s most recent guidelines for gonorrhea treatment (issued in 2012) recommend only using cefixime when the preferred option — ceftriaxone-based combination therapy — isn’t available. And the CDC’s new report doesn’t indicate any recent waning in the effectiveness of that combination therapy.

Still, indications of antibiotic resistance among any gonorrhea treatment is considered troubling, the study authors said.

“It is essential to continue monitoring antimicrobial susceptibility and track patterns of resistance among the antibiotics currently used to treat gonorrhea,” said study lead author Dr. Robert Kirkcaldy, an epidemiologist in the CDC’s division of STD prevention in Atlanta.

“Recent increases in cefixime resistance show our work is far from over,” he said.

The study findings are published as a research letter in the Nov. 3 issue of theJournal of the American Medical Association.

The CDC noted that gonorrhea is spread during unprotected vaginal, anal or oral sex. The sexually transmitted infection is particularly common among youth and young adults between the ages of 15 and 24.

Many people have no symptoms when infected. When symptoms do occur, they may include a painful or burning sensation when urinating; painful, swollen testicles and discolored discharge from the penis among men. In women, symptoms may include increased vaginal discharge and vaginal bleeding between periods. Rectal infections may spark soreness, itching, bleeding, discharge, and painful bowel movements, the CDC said.

If gonorrhea goes untreated, “serious health complications” can result, Kirkcaldy said. Those can include chronic pelvic pain, infertility and life-threatening ectopic pregnancy — an abnormal pregnancy that occurs outside of the uterus. In rare cases, gonorrhea can spread to your blood or joints, causing a potentially life-threatening infection, the CDC warned.

But when identified, antibiotics can provide an effective cure for those with gonorrhea.

The new CDC study looked at treatment outcomes among male gonorrhea patients who had been treated at public clinics across the United States between 2006 and 2014.

More than 51,000 samples were gathered across 34 cities. About one-third were collected in the western United States and one-third collected in the South. A little more than a quarter of the samples were drawn from men who either identified as gay or bisexual, the study said.

The investigators found that the CDC’s 2012 shift away from recommending cefixime and toward ceftriaxone-based combination therapy had a profound impact: while the combination therapy had been given to less than 9 percent of the patients in 2006, that figure shot up to nearly 97 percent by 2014.

Alongside that shift, the team found that cefixime-resistance went up from 0.1 percent in 2006 to 1.4 percent in 2011, and then back down to 0.4 percent in 2013. But by 2014 resistance trended upward to 0.8 percent, the research revealed.

What does this mean? “Trends of cefixime susceptibility have historically been a precursor to trends in ceftriaxone,” said Kirkcaldy. “So it’s important to continue monitoring cefixime to be able to anticipate what might happen with other drugs in the future.”

“The task force recommends screening for gonorrhea in sexually active women age 24 years or younger, and in older women who are at increased risk for infection,” she said.

The task force doesn’t advocate for or against screening for men, saying more research is needed to prove effectiveness. However, Kirkcaldy said that the “CDC recommends an annual gonorrhea screening for high-risk sexually active women and for sexually active gay, bisexual, and other men who have sex with men.”

Like this:

One of the problems with removing brain tumors is ensuring no cancerous tissue remains so they do not regrow. Now, a new study promises to reduce this problem – scientists have discovered a way to highlight a protein on brain scans so the edges of a tumor can be seen more clearly.

Researchers have found a promising way to show the edges of brain tumors in MRI scans more clearly.

The study, which offers scientists the most complete picture of brain tumors yet, is the work of a team from the University of Oxford in the UK, and was presented on Monday at the National Cancer Research Institute (NCRI) Cancer Conference 2015, in Liverpool, UK.

The edges of a tumor contain the most invasive cancercells. For surgery or radiation therapy to succeed, doctors need good maps that show not only where the tumor sits in the brain, but also where its edges are – a clear delineation between cancerous and healthy tissue.

This is important not only in order to remove all the cancerous tissue, but also because the most invasive cells are at the edge of a tumor, as one of the researchers, Cancer Research UK scientist Nicola Sibson, a professor in the Institute for Radiation Oncology at Oxford, explains:

“If we can’t map the edge of the tumor, surgery and radiotherapy often fail to remove aggressive tumor cells – and the brain tumor can grow back.

Currently, on magnetic resonance imaging (MRI) scans, you can see where the brain tumor is, but its edges are blurred. This is because the MRI spots leaky blood vessels inside the tumor. But on the edges of the tumor, the blood vessels are intact, so they do not show as clearly on the scans.

Highlights edges of both primary and secondary brain tumors

Now, for the first time, Prof. Sibson and her team have discovered a useful protein inside the blood vessels at the invasive edge of brain tumors.

In tests on rats, they showed it is possible to use the protein to define the edges of both primary and secondary tumors on MRI scans.

The protein – called VCAM-1 – is released as part of an inflammatory response caused by the brain tumor. The researchers developed a special dye that recognizes and sticks to the protein. The dye highlights the protein – and thus the edges of the tumor – on MRI scans.

An added advantage, note the researchers, is that the protein is on the inside of the vessels, so the dye can access it from the bloodstream.

Prof. Sibson concludes:

“This research shows that we can improve imaging of brain tumors, which could help both surgeons and radiotherapists with more effective treatment.”

Every year, around 256,000 people worldwide are diagnosed with cancer in the brain or another part of the central nervous system. In the UK, where the study was conducted, this figure is around 9,700, or 27 people a day.

“Brain cancers continue to have very poor survival rates,” says Harpal Kumar, chief executive of Cancer Research UK, which co-funded the study with the Medical Research Council. Kumar adds:

“The holy grail would be to be able to completely remove brain tumors with the help of this new imaging technique – reducing recurrence of the disease and saving more lives.”

Like this:

Researchers in the US have developed a new drug that can be delivered directly into the eye via an eye dropper to shrink down and dissolve cataracts – the leading cause of blindness in humans.

While the effects have yet to be tested on humans, the team from the University of California, San Diego hopes to replicate the findings in clinical trials and offer an alternative to the only treatment that’s currently available to cataract patients – painful and often prohibitively expensive surgery.

Researchers in the US have developed a new drug that can be delivered directly into the eye via an eye dropper to shrink down and dissolve cataracts – the leading cause of blindness in humans.

While the effects have yet to be tested on humans, the team from the University of California, San Diego hopes to replicate the findings in clinical trials and offer an alternative to the only treatment that’s currently available to cataract patients – painful and often prohibitively expensive surgery.

Affecting tens of millions of people worldwide, cataracts cause the lens of the eye to become progressively cloudy, and when left untreated, can lead to total blindness. This occurs when the structure of the crystallin proteins that make up the lens in our eyes deteriorates, causing the damaged or disorganised proteins to clump and form a milky blue or brown layer. While cataracts cannot spread from one eye to the other, they can occur independently in both eyes.

Scientists aren’t entirely sure what cases cataracts, but most cases are related to age, with the US National Eye Institute reporting that by the age of 80, more than half of all Americans either have a cataract, or have had cataract surgery. While unpleasant, the surgical procedure to remove a cataract is very simple and safe, but many communities in developing countries and regional areas do not have access to the money or facilities to perform it, which means blindness is inevitable for the vast majority of patients.

According to the Fred Hollows Foundation, an estimated 32.4 million people around the world today are blind, and 90 percent of them live in developing countries. More than half of these cases were caused by cataracts, which means having an eye drop as an alternative to surgery would make an incredible difference.

The new drug is based on a naturally-occurring steroid called lanosterol. The idea to test the effectiveness of lanosterol on cataracts came to the researchers when they became aware of two children in China who had inherited a congenital form of cataract, which had never affected their parents. The researchers discovered that these siblings shared a mutation that stopped the production of lanosterol, which their parents lacked.

So if the parents were producing lanosterol and didn’t get cataracts, but their children weren’t producing lanosterol and did get cataracts, the researchers proposed that the steroid might halt the defective crystallin proteins from clumping together and forming cataracts in the non-congenital form of the disease.

They tested their lanosterol-based eye drops in three types of experiments. They worked with human lens in the lab and saw a decrease in cataract size. They then tested the effects on rabbits, and according to Hanae Armitage at Science Mag, after six days, all but two of their 13 patients had gone from having severe cataracts to mild cataracts or no cataracts at all. Finally, they tested the eye drops on dogs with naturally occurring cataracts. Just like the human lens in the lab and the rabbits, the dogs responded positively to the drug, with severe cataracts shrinking away to nothing, or almost nothing.

“This is a really comprehensive and compelling paper – the strongest I’ve seen of its kind in a decade,” molecular biologist Jonathan King from the Massachusetts Institute of Technology (MIT) told Armitage. While not affiliated with this study, King has been involved in cataract research for the past 15 years. “They discovered the phenomena and then followed with all of the experiments that you should do – that’s as biologically relevant as you can get.”

The next step is for the researchers to figure out exactly how the lanosterol-based eye drops are eliciting this response from the cataract proteins, and to progress their research to human trials.

Like this:

Vast floating islands of plastic are just a drop in the ocean compared with what’s lurking deeper down. Between 5 and 13 million tonnes of plastic debris entered the marine environment in 2010 – and most of it is under water. What’s more, without improvements in the way we manage waste, it could be 10 times as much each year by 2025.

Now we know there’s even more missing plastic than that.Jenna Jambeckat the University of Georgia, Athens, and her colleagues have looked at data on plastic use and disposal in 192 coastal countries. They calculate that between 4.8 and 12.7 million tonnes entered the world’s oceans in 2010 alone. This means the amount of plastic that has entered the ocean down the years might be 1000 times more than the mass of floating plastic that scientific surveys have measured.

Surprisingly, the 10 countries with the largest problem – many of which are in south-east Asia – generally have relatively low rates of plastic waste generation per person. For instance, in China – which tops the list with an estimate of up to 3.53 million tonnes of plastic marine debris a year – the average person generates about 1.1 kilograms of waste per day of which just 11 per cent is plastic. In the US – at 20 on the list – the average person generates more than twice as much waste. But the top offending countries also have high coastal populations and low rates of plastic recycling.

It’s an interesting study, saysMarcus Eriksenof the Five Gyres Institute in Los Angeles, who led last year’s floating plastic study

– but some of the assumptions used to arrive at the new calculations could be quibbled with. “I believe the authors underestimate the amount of trash that is scavenged, burned and buried before it reaches the ocean,” he says. “I think there’s much less leaving land.”

Even so, there is clearly a huge mismatch between the plastic entering the ocean and the plastic we find there. “The disturbing conclusion is that much of the plastic entering the oceans is unaccounted for,” saysCarlos Duarteat the King Abdullah University of Science and Technology in Saudi Arabia, who has also helped conduct surveys into the amount of plastic in the oceans.

Plastic smog

Where is the missing plastic? Perhaps it’s hiding in plain sight. “It’s important to understand that plastic shreds rapidly into microplastics that distribute widely into the most remote waters on the planet,” says Eriksen. “Of the 5.25 trillion particles of plasticwe reported recently inPLoS One, 92 per cent are less than the size of a grain of rice.”

Such small particles spread throughout the water column, says Eriksen, also finding their way intosea-floor sedimentsand ice cores. That means we should stop thinking of plastic waste in terms of unsightly chunks of debris floating in vast oceanic garbage patches, and instead see it more as a pervasive “plastic smog” of tiny particles spread through the entire volume of ocean water.

“It’s not sensible to go to the ocean with nets to capture trash, but rather to focus on mitigation strategies on land,” says Eriksen.

Yet the amount of plastic entering the ocean is likely to keep rising in the years to come. Jambeck and her colleagues point out that 16 of the top 20 plastic producers they identified are middle-income countries, where strong economic growth will probably result in even more plastic use, but where the infrastructure to deal with the waste is still lacking.

But the solution isn’t to burden these developing countries with the cost of building effective waste management infrastructures, says Eriksen. Instead, we should require the plastics industry to rethink the way it designs its products – in particular, the industry should phase out plastic products designed for single use.

Change the way plastic is produced, says Eriksen, “and the plastic pollution issue would largely diminish”.

The researchers, including Amanda Bakian, PhD, an assistant professor of psychiatry at the University of Utah in Salt Lake City, publish their findings inThe American Journal of Epidemiology.

This is not the first study to find a link between air pollution and increased risk of suicide. A2010 studypublished inThe American Journal of Psychiatryfound people from over seven cities in South Korea were 9% more likely to commit suicide within 2 days of a rise in air pollution.

And last year, Bakian and colleagues conducted a study that found residents of Salt Lake County were more likely to commit suicide within 3 days of being exposed to increased levels of nitrogen oxide or high concentrations of fine particulate matter (PM 2.5) – particles in smoke and haze that are 2.5 micrometers in diameter or less.

They build on these findings with their latest study, which found middle-aged individuals and men are most at risk of suicide through exposure to air pollution.

Short-term air pollution exposure ‘increased suicide risk by up to 25%’

The team analyzed the records of 1,546 people in Salt Lake County who committed suicide between 2000 and 2010.

Consistent with their previous findings, the researchers calculated that individuals who were exposed to increased levels of nitrogen dioxide were 20% more likely to commit suicide in the following 3 days, while those exposed to higher concentrations of PM 2.5 were 5% more likely to take their own lives within the next 3 days.

Men were found to have an even higher risk of suicide following air pollution exposure; after exposure to increased levels of nitrogen dioxide and PM 2.5, their risk of committing suicide in the following 3 days was 25% and 5%, respectively.

For individuals aged 36-64, the researchers found that short-term exposure to high levels of nitrogen dioxide increased the risk of suicide by 20%, while short-term exposure to high concentrations of PM 2.5 was linked to a 7% increased suicide risk.

Commenting on their findings, Bakian says:

“As suicide risk was found to differ by age and gender, this suggests that vulnerability to suicide following air pollution exposure is not uniform across Salt Lake County residents and that some Salt Lake County residents are more vulnerable than others.

Our next step is to determine in more detail exactly what elements – such as genetic and sociodemographic factors – are responsible for increasing one’s vulnerability to suicide following air pollution exposure.”

The researchersstressthat their findings do not indicate that short-term exposure to air pollution is a direct cause of suicide. Instead, they suggest that increased air pollution may merge with other factors that drive suicide risk.

The American Cancer Society (ACS) funded study suggests estimates from the Surgeon General that show smoking kills about 480,000 people in the US every year, exclude tens of thousands of Americans who die from diseases not counted as caused by smoking but perhaps should be.

For their analysis, Dr. Eric J. Jacobs, strategic director of Pharmacoepidemiology at the ACS, and colleagues reviewed data from 5 large studies, including the ACSCancer Prevention Study-II, the Health Professionals Follow-up Study, the Nurses’ Health Study, and the National Institutes of Health AARP Diet and Health Study.

The data covers nearly a million Americans aged 55 and over that were followed for about 10 years, during which time there were over 180,000 deaths, including nearly 16,500 among current smokers.

As expected, the analysis showed current smokers were nearly three times more likely to die in that time than people who never smoked.

Most of the excess deaths in smokers were due to diseases that are known to be caused by smoking. These include 12 types of cancer, stroke, coronary heart disease and chronic obstructive pulmonary disease (COPD – which includes chronic bronchitis, emphysema and chronic obstructive airways disease).

Smokers had double risk of death from diseases not classed as caused by smoking

However, Dr. Jacobs and colleagues also found that around 17% of the excess deaths in current smokers were attributed to diseases outside of the list of 21 that the US Surgeon General classes as caused by smoking and so are excluded in official estimated US deaths due to tobacco use.

Fast facts about smoking

Tobacco use is the leading preventable cause of death worldwide

Smoking and tobacco use costs the US $289 billion a year, including more than $156 billion in lost productivity

In 2011, the tobacco industry spent nearly $23 million a day on promoting and advertising cigarettes.

The investigators drew particular attention to where they found a double risk of death among current smokers due to diseases such as intestinal ischemia (narrow or blocked arteries in the gut), kidney failure, infections, hypertensive heart disease and various types of respiratory disorders outside of COPD.

The authors note that even though these diseases are not officially regarded as being a result of smoking, and are therefore excluded from estimates of smoking-related deaths, there is strong evidence to suggest they are.

Their analysis also showed that excess risk of death from each of these conditions fell when participants gave up smoking.

The team found smoking was also tied to smaller increases in risk of death from breast cancer, prostate cancer and cancers of unknown sites. These diseases are currently not formally classed as being caused by smoking.

The authors conclude that the number of additional deaths potentially linked to smoking is significant and may be due to diseases not formally established as caused by smoking. However, should future research show they are, then they should be included in estimates of the death toll from tobacco use.

The study only covered data on one million people taking part in large studies, but Dr. Jacobs says:

“If the same is true nationwide, then cigarette smoking may be killing about 60,000 more Americans each year than previously estimated, a number greater than the total number who die each year ofinfluenza or liver disease.”